The electronics industry has experienced an ever increasing demand for smaller and faster electronic devices which are simultaneously able to support a greater number of increasingly complex and sophisticated functions. Accordingly, there is a continuing trend in the semiconductor industry to manufacture low-cost, high-performance, and low-power integrated circuits (ICs). Thus far these goals have been achieved in large part by scaling down semiconductor IC dimensions (e.g., minimum feature size) and thereby improving production efficiency and lowering associated costs. However, such scaling has also introduced increased complexity to the semiconductor manufacturing process. Thus, the realization of continued advances in semiconductor ICs and devices calls for similar advances in semiconductor manufacturing processes and technology.
Generally, the minimum feature size of a given semiconductor IC is a function of the wavelength of a radiation source used in a lithography process, as well as a resist composition and resist selectivity, among other factors. As semiconductor lithography has progressed, the wavelength of the radiation source used has decreased, and the radiation source itself may be relatively weak, such that photoresists have been designed to utilize radiation sources as efficiently as possible. As one example, chemically amplified photoresist (CAR) compositions have been introduced in an effort to increases a resist's sensitivity to an exposing light source. However, CAR systems have encountered limitations which are difficult to overcome, such as poor photon absorption in thin films, moderate etch selectivity, and limited gains in resolution. Moreover, the need for photoresists with high resolution, low line width roughness (LWR), and high sensitivity has increased more rapidly than the capability provided by such CAR systems. As such, chemically amplified resists alone may not be able to satisfy the next generation lithography requirements demanded by the continued advances in semiconductor technology.
Thus, existing techniques have not proved entirely satisfactory in all respects.